Did you make this instructable?

It would have to be fairly accurate, and probably a white material (that the laser will make dark spots on). This is due to the way laser scanners work. They're fairly precise instruments so the barcodes have to be perfectly spaced. The only way this is really feasible is if you have a laser etching machine. Good Luck!

I've tried and tried to hand draw barcodes and they never seem to work - the tolerances are just too tight. Laser etched should work so long as the reader 'sees' the white areas and 'doesnt see' the dark areas. (same applies to reflectivity as plain white paper, but etching plastic would be 'white' where you etch, and black where its transparent)